Antibodies were first employed in tissue section analysis in 1942 to visualize pneumococcal antigens in organ biopsies from mice infused with live bacteria. Since that time, immunohistochemistry has become a mainstay of clinical diagnostics and basic research.
However, conventional immunohistochemistry methods are limited in that they are only able to assess the spatial distribution of one, two or three (rarely more) epitopes in a tissue section. This constraint limits the application of immunohistochemistry in clinical diagnostics, in which field it is very desirable to analyze a much larger number of epitopes. Newer methods for epitope detection in a sample have been described and involve, for example, labeling a capture agent with DNA and subsequently detecting this DNA by primer extension, e.g., as in WO 2015/200139 and US 20150368697.
The present method is automatable and allows for a highly multiplexed analysis. As such, the method is believed to meet some of the deficiencies of conventional immunohistochemistry methods.